Promises
by FrankieFandom
Summary: One reckless driver, a helicopter ride and a promise.
1. Crash

**Promises**

 **Crash**

Severide had been staying at Casey's house ever since he had discovered what a terrible state Casey was living in after Hallie had died. It had taken some convincing but Casey had finally broken down and allowed him to stay, only on the condition that he slept in the spare bedroom whilst Casey still slept on the couch. Despite Severide's protests to the contrary Casey refused to take the spare room, nor would he sleep in the main bedroom he had shared with Hallie.

Casey hadn't been himself at work, he'd thrown himself into it all as a distraction just like he would always do only this time everyone could see how his cracks had started to show. When Severide had heard what had happened when Casey and some of his crew were trapped in the prison he'd had enough, he couldn't stop himself from intervening. That was when he had found out what a state Casey was truly in but it was a few more shifts before Casey had taken furlough, somewhat forced by Boden. Once Severide had discovered his living situation and once the funeral had taken place everything had fallen apart. Casey couldn't hold himself together any longer.

The thing not everyone understood about Hallie was that she had been one of the only constant people in Casey's private life. He'd known her for more than eight years. They'd had their ups and downs, they'd had a couple of short breaks. Casey figured he was hard to live with, difficult to be around. As Hallie had always said, he kept everything buried so deep within himself that she was scared one day he would break and she wouldn't be able to help him. But he had opened up to her, he began to trust her completely, making small comments about his past, gradually revealing his story. She was the first person he had ever fully explained the situation with his mom to. But as the years had gone by Hallie had wanted her career, she'd not felt ready to settle down and have the family that Casey so longed for. He understood her reasons but he still wanted children of his own. His very own family unit. Something he had always really lacked in his life. Hallie had a family, a big family, it was one of the reasons she didn't long for the same wish as Casey. They'd broken up over that but when she'd arrived back in his life a few weeks ago she knew what she wanted, she'd grown in their time apart, and she'd wanted to have a family with the man she loved.

"Casey?" Severide called into the closed bathroom door. "You all right? We should really get going if we wanna get there before it starts getting dark." They were going away for a week. Fishing. He had taken furlough so he could get Casey away from the city for a much needed break. Casey needed to take a break and Severide knew he couldn't go anywhere on his own with all the monsters and demons that were in his head.

Casey was stood in front of the bathroom mirror. He had been for the last ten minutes. He couldn't see the reflection that was staring back at him. He was deep in thought. Thinking about everything and absolutely nothing all at the same time.

"Matt?" he heard Severide call again, it wasn't hard to detect the concern in his tone. He would admit to being a little surprised at Severide's insistence that he stayed with him, that he drove Casey to the funeral, went out after the wake and took him home after he'd drank so much he could hardly walk, and now Severide was taking him away, insisting that it would be good for both of them to leave the city. They had reconciled after Andy had died all those months ago. Both of them had made mistakes, both had blamed, even hated themselves and each other for what had happened. Still did to a degree but at least they had stopped butting heads even though things weren't back to how they were before Andy had died. Casey had really not expected so much care and help from the very person who had blamed him entirely for the demise of their best friend. "Matty?" Severide's voice floated through the closed door again. There it was; that name, the name only Severide used because he was the only one who'd ever been allowed to say it.

On the other side of the door Severide was counting from one to ten in his head, getting ready to kick it open. This wasn't the first time Casey had locked himself in the bathroom and ignored Severide calling him. But he relaxed as he heard Casey's voice a few moments later. "I'm ready," Casey spoke quietly and Severide heard the bathroom door unlock.

They'd been on the road for a few hours. Casey was driving. They were in his truck since it was much easier to take everything they needed for the week in his vehicle rather than attempt to fit it all into Severide's car. There'd been silence in the car for most of the journey, the only spoken words were of insignificant things. Casey was wound so tight Severide was sure he was likely to explode at any moment. He always had wondered how Casey had managed everything, no one had it perfect in life, you could look at anyone and think they were perfect, think they had the perfect childhood, the perfect lives, but you would never really know. Severide knew he could have had a worse childhood, hell, everyone could have it worse but then there was Casey. Casey. Severide had found himself thinking about him so much recently. He'd not had something terrible done to him, not truly terrible. He'd not been the most abused kid in the city, not even close, but what had happened to him would count as abuse, it could have been so much worse though, he was lucky really, lucky that his mom had killed his dad but not lucky because he had loved his dad, his dad hadn't beaten him senseless, well, there had been one incident but on the whole Casey had loved his father, still loved his father, always would.

Severide would never truly understand why but he always saw Casey as the better person. He was always seen as the better person by everyone, he was blond and attractive and everyone loved him, there was a few exceptions, but on the whole everyone loved Casey, victims loved Casey. He looked like the perfect model for a firefighter. Severide knew more. He wasn't perfect, he had so many issues, he had his faults, but he always tried to shield his issues away and it did make him seem like he had the perfect life because that's what he wanted everyone to think, he didn't want anyone to know his history, his issues. Severide could remember the day everyone at 51 had found out about his family. He'd blamed Severide immediately because it had never even crossed his mind that it could be Andy or someone from outside of the firehouse, since Severide knew more about him than anyone else. All those years previously everyone at the academy had discovered Casey's situation because Griffin had recognised his surname. Severide had desperately tried to put the dampers on the rumours both times Casey's name had been tossed around like celebrity gossip. In the end Herrmann spoke to Casey in private, Severide never knew what he said, but everything went back to normal after that and there'd been hardly a mention of Casey's family since.

"Matt…" Severide began as they drove along.

Casey glanced over to him

"You know you don't have to be so perfect all the time, we're all allowed to have faults, you should give yourself a break."

Severide watched as Casey's brows furrowed, he was concentrating on the empty road ahead. It was starting to rain now. "I'm not perfect," Casey retorted, he nearly laughed at the idea.

"You try to be… you try to _appear_ to be," he explained.

"I'm not trying to be perfect," Casey almost snapped.

"You try to hide all your flaws," he replied.

"Everyone does that Kelly." Casey shook his head, frustrated. "What are you doing?"

"I just…" he sighed, he really wasn't doing a very good job at explaining his thoughts, "I just think you should relax and…"

"Relax?" Casey shot back. "My fiancée was just killed and you want me to relax."

"You're allowed to breakdown…"

"What the hell do you think this is?" Casey couldn't stop himself from yelling. "Do you think all this is me trying to be perfect? You saw the state of my…"

"Matt, no." Severide shook his head. "I'm explaining it all very badly. I just, I mean, you can talk, you can talk to me about stuff, you can cry and…"

"You think I've not cried? You think I've not screamed and…"

"I think you should stop being so hard on yourself."

Casey's eyes remained on the road, he was silent for a few moments. "Well… you went a funny way about saying it," he paused, sighing, "I'm sorry… I'm just… I guess I'm just on edge right now, taking stuff out on you isn't fair. Sorry."

"Take it out on me, I don't care," Severide shrugged, "Just promise me one thing?"

"What?" he asked, glancing over.

"Don't take it out on yourself." When Casey said nothing Severide spoke again. "You have to promise me, Matt?" he exhaled, "You won't make a promise you know you'll break."

"Sorry."

"You're so fucking broken."

Casey just laughed at that. Laughing purely for the first time Severide had seen since before Hallie's death. "I don't think I'm as broken as you think am," he spoke through the laughter. He slowed the car as they reached a crossroad, stopping at the stop sign he looked and then drove on.

Suddenly Severide saw something from the corner of his eye. "Casey look out!" he yelled. Casey had already seen it and had quickly swung into action but it was too late. The car had been speeding down the road from their left, straight towards them on the crossroad. Casey slammed his foot on the break but it made no difference.

In less than a matter of seconds the red blur that had been hurtling down the road slammed into the side of the truck sending it careering down the road. Metal crumpled. Breaks screeched on the wet tarmac. The truck flipped knocking both Casey and Severide out cold. It flipped again, flinging their bodies around like rag dolls. The car then skidded off to the left, only coming to a stop when it collided with the pine trees at the side of the road. Momentum eventually stopped the truck, it slowed to a halt as it continued to travel sideways down the road.

Casey woke in pain. He could hear ragged breaths. Moaning. He could hear the soft patter of rain. Metal creaking. Birds twittering. He could smell blood. He could taste blood. Everything hurt. He forced his eyes open. It took him some time realise that what he thought was a delicate cobweb in front of him was actually the cracked glass of a windscreen. Realisation hit. Suddenly he could understand why he was in pain. Kelly. Kelly. Kelly. His mind was shouting at him. Panicking. His body wouldn't cooperative with his wishes. He couldn't turn his head. He couldn't move.

"Kel…" he breathed. His voice was louder the next time, "Kel…" he tried to rouse him, it wasn't working. Casey coughed. The coppery substance he could taste grew stronger. Horrible images entered his mind. Severide's eyes wide open. Bloodshot. Unseeing. "Kel…" he spoke as he managed to look to his right, his body finally cooperating.

Severide woke with a start. His eyes shot open. A groan escaped his lips. It took him a moment to remember everything that had happened and then he heard Casey's voice. "Matt…" he began, "Matt, are you ok? Are you hurt?" His heart had been in his mouth when he'd realised the car was going to hit Casey directly and there was nothing he could do about it, nothing he could to protect him. He didn't care about the pain he could feel radiating from his shoulder or the throbbing in his head, he just needed Casey to tell him he was all right.

"Gonna ask…" Casey coughed out, "Gonna ask you the same thing…"

"Shoulder's busted but I'm all right… I think. Are you hurt?" he repeated, so much concern in his tone, he wasn't going to hide his worry, the fear he'd felt when he saw the car speeding towards Casey's side of the truck was almost unreal. He couldn't lose Casey. Not Casey.

"Bit winded. I'm fine though, I'm fine." Casey smiled wearily towards him. "Don't really… really remember…" he frowned, everything was all still a bit of a blur. Red. Screeching. Pain.

"Your door…" Severide began, trying to hide his concern as the sight of blood on his best friend, it wasn't much at least. Broken glass from the window had cut his skin. Bruises were already appearing. He was pale. But he was awake. He was breathing. His heart was beating. He was alive. "Can you open your door? Can you move?" he asked.

"Jammed," Casey replied. The left hand side of the car had concaved inwards, Casey didn't have any space to manoeuvre.

"Can you move?" Severide questioned again as he managed to get the passenger side door open.

"I'm fine, I'm all right… think we've been really lucky…" he spoke, pulling himself out of the mess of metal, moving slowly and carefully to follow Severide out of the wrecked truck.

Severide faltered a little as he stood up out of the truck, he could feel a fresh trickle of blood making its way down his face. He held out a hand for Casey, helping him over the seats and out of the car. "Ok?" he asked.

Casey just nodded. There was a horrible feeling in his chest that was only getting worse. It was sharp. Stabbing. His back hurt. He was struggling not to cough. Struggling not to just fall into Severide's body and let himself be held. Adrenaline won through. "The other…" he glanced around and spotted the car that had hit them at such a terrifying speed. "The driver?" he questioned.

"Hit us head on at whatever ridiculous speed they were driving at…"

"I didn't see them… not 'til it was too late…" Casey spoke as he slowly started making his way over the other vehicle. Doubting the survival of anyone inside.

"They went straight through the stop sign," Severide replied as he followed Casey closely. "Not your fault." He didn't miss the way Casey staggered, didn't miss how he struggled to walk in a straight line, how he had to pause every so often, and he didn't miss the way Casey practically collapsed on the side of the car as they reached it. "Matt you should…" he began.

"I'm all right," Casey protested. Looking inside they could see there was just the driver. He was breathing but barely. Severide could only make out a faint pulse. Casey could see how his skull had concaved on impact. He doubted he'd make it even if an ambulance turned up in the next minute. And just as that thought entered his head he spoke, "Call an…"

With a bloody hand Severide was already pulling his cell phone out of his pocket, "On it… Damnit…"

"What's wrong?" Casey questioned, trying to get the car door open.

"No reception," he sighed.

Casey turned to him. "What?"

"No reception," Severide repeated.

"Erm… ok…" His mind blanked as he turned back to the man in the car. "Erm… I need…"

"Matt, he's dead," Severide stated, fingers back on the man's neck.

"Erm… right… my phone's in the truck," he spoke, looking at the body still and resting more of his own weight on the side of the car. "That might… might work…"

Severide's concern for Casey was growing by the second. "Matt?" He held his arm, steadying him.

"I'm all right, just a little dizzy, I'm fine… you need to get that shoulder looked at… it could be… erm…"

"Don't move, ok?"

"I'm all right…" Casey slurred, his hand gripping tightly onto the car for support.

"You say that one more time and I'll throttle you," he threw back over his shoulder as he went to the truck.

Severide should have known better. Of course Casey hadn't listened to him. As he started walking back, Casey's phone now in his jeans pocket, Casey had begun making his way over to him. Severide was shaking his head at both the fact that there was no signal, because apparently that was the way their luck was going, and because Casey hadn't listened to a word he'd said. Severide was about to make a remark on Casey's inability to do anything that was good for him when he saw him falter. Casey's knees buckled after only a couple of steps and he fell forwards with a sickening thud.

 **TBC**


	2. Flight

**Promise**

 **Flight**

"Matt!" Severide screamed. He ran over to Casey's fallen body as fast as he could, his body jarred with each step, he forgot all about the agony his right shoulder felt. He fell to his knees. "Matt? Speak to me…" His fingers searched for a pulse as his eyes watched Casey's chest movements and there it was, his heart was beating and he was breathing. But it was too slow. Too shallow.

Casey's eyes flickered open, Severide's face blurred in and out of focus as he spoke, "About… what you… said… might be a… bit… bit broken now…"

"Where does it hurt?" Severide asked, helping Casey as he moved to sit up.

"Chest..." he admitted.

"You idiot," Severide muttered under his breath. Of course Casey had been more worried at everyone else but himself. Quickly Severide slipped off his jacket and laid it under Casey's head before gently lowering him back down.

"Ambo? You're bleeding…" he spoke quietly, looking up at the wound above Severide's eye.

"Need to find some signal," Severide replied, gently lifting up Casey's shirt. There was a bruise blossoming on the entire left hand side of his chest. "Reckon you've broken your ribs…" he spoke aloud, still shocked at the amount of bruising on Casey's body, although really after such a crash he should have expected it. He was more shocked that Casey had managed to get out of the truck on his own and check on the other driver before succumbing to his injuries.

"Lung contusion," Casey began, "Coughing up… up blood… not much. Not dying yet. Don't worry." He smiled through gritted teeth. Now the adrenaline had worn off he could feel himself fading quickly but he was still trying to hide his fears from Severide. "How's… how's your arm… shoulder?" he asked.

"Matt, I'm not the one who's bleeding internally." He pulled out his phone in hope of finding just one bar of signal, "Damnit…" he swore. He looked around. They really were in the middle of nowhere, they'd hardly passed any cars during the last hour of their journey, he just hoped one would come by now. Preferably with a doctor and lot of medical equipment on board but that was asking for a miracle.

Casey's strained voice broke his thoughts. "You're not gonna… gonna get signal down here…"

"I know, I know." He nodded. He didn't want to leave Casey, not like this, but he didn't have a choice. "You gotta stay awake, ok?" he spoke, leaning down over Casey now, their faces only inches away from each other.

"Yeah… yeah… know the drill…" Casey mumbled.

Severide stood up, glancing down at Casey once more. He felt helpless out here, despite all his training there was nothing he could do. He went back to the truck, pulled out a couple of blankets, thankful of Casey's preparation for their trip. Back at the side of the road he dropped down to Casey's side, draping the blankets over him, it was still raining, it wasn't heavy but he was getting wet and he was going to get cold. Casey's eyes had slipped closed. "Matt, what did I say?" he asked abruptly.

Casey's eyes remained closed as he mumbled, "I'm awake…"

"Stay that way," he said as he got back up, staving off another dizzy spell, his head was throbbing madly. "I'll be back."

Every step Severide took pained him but he did it, he kept going until he found signal on his phone and thankfully it wasn't one of those rather unfortunate moments like in the movies where the phone would immediately run out of battery. He dialled 999 then made his way back down to Casey, still hoping another car would drive by that he could flag down because he just wanted to get Casey some medical attention and fast. He was a trained EMT but they had no equipment and he knew internal bleeding was a scoop and run situation so there was little he could do.

Casey's eyes opened when he heard the sound of Severide's footsteps. He'd struggled but Severide's insistence that he remain awake won through, his voice had been on repeat in Casey's head as he battled with unconsciousness. His breathing had worsened. The pain had increased and when he coughed and spluttered more and more blood appeared. But he wasn't going to let Severide down. Not again.

"Ambo's on the way, and air evac," Severide told him. He'd requested rapid transport because traveling by air meant Casey would get treatment faster, there would be a doctor on board, and they could take him to the facilities he needed most rather than just the closest hospital which may not be fully equipped for his needs. An ambulance had still been dispatched with the off chance the EMT's arrived on the scene first and they'd need to take away the body of the other driver.

"ETA?" Casey slurred out.

"Could be forty minutes before anyone gets to us," he responded but Casey's eyes had closed. "Matt?"

Casey forced his eyes open. "I need…" he coughed and spluttered, "Need you to… do something… for me…"

Severide waited for Casey to continue.

"Back of the truck… black bag… knife… need a pen or something… first aid…"

Without questioning him Severide got up and rushed over to the wreck of the truck, not caring about his own injuries and pain. Quickly he grabbed everything Casey'd asked for before rushing back, landing on his knees by his side. Casey's eyes were closed, and he noticed now how pale he seemed, how fragile he looked. "Matt?"

"I need… I need you…" He was struggling to speak now, struggling to stay awake, struggling to breathe. "My… my lung's collapsed… you have to…"

"No," Severide responded quickly, already understanding what Casey was about to suggest. "Medics will be here soon. There'll be a doctor on that flight…"

"Can't… breathe…" he struggled.

"What do I do?" Severide asked after a moment, forced courage lacing his voice because this was Casey. This was his best friend. His Casey. His brother.

"Fifth intercostal space… mid axillary line…" he began, he was slurring his words now. He'd always listened to Hallie as she'd spoken aloud whilst studying. He smiled for a moment recalling how she used to trace his skin, listing the names of his bones, listing the types of incision lines, listing symptoms and recalling treatments all in order to help her study.

Severide's abrupt voice brought him back to reality. "Matty… Matt, stay with me."

"Erm…" he swallowed thickly, there was a copper taste in his mouth. "Erm... mid axillary line… find… you gotta find the space between… between fifth… sixth ribs… left side…"

"Casey… Matt…" he was shaking his head now. "I can't… I can't…"

"Easy…" Casey wheezed, barely able to take a breath, "Saw Hallie… do it… loadsa… times…" It was a white lie but he didn't have much choice, he knew Severide could do this, he just needed the reassurance.

"I'm not a doctor… I never even did it with a needle on a real person… I don't think I should be doing this." Of course he wanted to help him but he didn't want to make anything worse.

Casey moved his left arm up, wincing as he did but he knew it was necessary. "Between the fifth and… and sixth…" he started to repeat. He needed Severide to do this. "Use the knife… insert the pen… should hear… should hear… hear air… then… then… cover up… erm… tape or… or something…" he tried to explain the best he could but he was fading fast.

"Matt, I don't know what I'm doing… I'll kill you…"

"Dead… anyway…"

Casey was right. If Severide didn't act soon Casey would be long dead before the paramedics or air evacuation crew arrived on scene. With a quick nod he stood up and went to gather a few more items he would need from the wrecked truck. He drew a long calming breath before he turned and went back to Casey's side. "You want some of this?" Severide asked, bottle of whiskey in his hand.

Casey managed a small nod, trying to hide the fear in his eyes. Severide knelt by him and supported his head while he took several large mouthfuls of the burning liquid, but he doubted it would do much to help the mind blowing pain he would soon be feeling.

"Kelly… I trust… I trust you," Casey spoke, letting his head fall back down onto Severide's jacket. "I… I know you… can… can do it."

Severide said nothing as he poured the whiskey onto Casey's bruised skin. He then took the ink cartridge out of the pen, chucking it away. He could hear Casey's breathing worsening by the second. He doused the knife, pen and his own hands with the alcohol. It was the closest they were going to get to a sterile scene. Taking another deep breath, he looked down into Casey's eyes, seeing the fear and the pain. "Are you ready?"

"I… I trust you," Casey simply repeated before closing his eyes tightly.

"I'm sorry Matt, I'm sorry…" Severide said under his breath to himself as he began to feel across Casey's ribcage for the correct position. He could scarcely stop his hands from shaking. "I'm sorry…" he said again as he lined up the sharp blade and started his work.

Severide was actually thankful when Casey passed out from the pain. He'd screamed when Severide had pierced his flesh with the knife, he'd tried so hard not to, he'd not wanted to let on how much it hurt but the noise that escaped his lips, that pure agonising sound, was involuntary. His nose and eyes ran and his blood smeared lips parted when his head rolled to one side as he fell into blessed unconsciousness. Severide hoped the worst was over as he manoeuvred a finger into the bleeding hole in Casey's ribs. He needed to make sure the depth was correct. If he went too far in he could easily pierce Casey's lung, not far enough and it wouldn't save his life. Satisfied he had got the depth right, he pulled his finger from the wound and shoved the pen in, hearing a satisfying quiet rush of air.

He sat back on his knees, letting out a sigh of relief as he saw Casey's chest begin to rise and fall more easily. His work was almost over. He tore off a strip of duct tape, pulled the pen from the wound and taped over the incision he had made, securing it with a few more strips of tape before he was satisfied they would hold it airtight. He checked Casey's pulse, finding it stronger and steadier now and he smiled down at his unconscious form. "You did good Casey. You did good." He pulled the blankets back up over Casey and sat back, letting out a deep breath, his hands shook as he looked down at the blood covered digits. Casey's blood. His heart jumped when he heard a moan escape Casey's lips. "Matty, you're all right, you're gonna be ok," he reassured him as he watched his eyes flicker open.

"Kel…" Casey groaned.

"I'm here, I'm right here."

"Hurts…"

"I'm sorry… I can't stop it from hurting, won't be long until you can get some meds, won't be long at all." But as Severide spoke he knew how long even a few minutes in pain felt. It would feel like a lifetime before the paramedics arrived. "You're breathing better," he nodded, "That's something."

Casey's eyes focused on his for just a moment, he was struggling to concentrate. "Thank you…"

Severide smiled, trying to lighten the mood. "Just don't ever ask me to do anything like that again, all right?"

"No promises…"

"Are you warm enough?" Severide asked, readjusting the blankets again, trying to make him as comfortable as possible and not sure what else he could do at this point.

"I… I don't know…"

Severide reached under the blankets and took Casey's hand, it was almost as cold as ice, his stomach plummeted. Casey's blood pressure was dropping dangerously low. His heart wasn't pumping enough blood around his body. His breaths were wheezy. He was still coughing up blood.

His fearful thoughts were interrupted by Casey's quiet voice. "How's… how's your head… arm?" he slurred.

"I'll be just fine Matt, don't you worry about me." Severide smiled down at him.

Suddenly a blank expression crossed his face. "What?" he frowned up at Severide. "What's hap… happening?"

Severide hesitated for a moment, fear growing. He shook his head, "Nothing, you've just got to keep your eyes open for me. You can do that, can't you?"

"Erm… sure…" Casey muttered, "Anything… anything for you."

Severide just looked down at him, not sure what to say.

Casey's voice broke the silence. "Kel…"

"Yeah bud?"

"Where… where are we?"

"You just need to stay awake, all right?"

"Mmm…" he mumbled, "Wait… what did you… did you say?"

Severide leant over Casey, sheltering him from the rain that was growing heavier. "Matt can you tell me what happened? Do you remember? I need you to tell me," he urged, speaking clearly, "Talk to me."

Casey's unfocused eyes looked up at him, he frowned. "You're bleeding…"

"Do you hear that?" Severide questioned suddenly, looking over to the source of the noise.

"Hear… hear what?" he coughed.

"Sirens," Severide smiled. He'd never been so happy to hear an ambulance before. "You're gonna be all right Matt," he said as the ambulance came to a stop, it had felt like an age since he'd first heard the sirens but had actually only taken a few seconds. The paramedics jumped out of the rig, grabbing their equipment and rushing over to the two of them.

Casey just stared up blankly as Severide relayed all the information to the paramedics, explaining how the other driver had died almost immediately after the crash, how Casey's lung had collapsed and he'd had no choice but to intervene. Casey barely noticed as the paramedics quickly moved the blankets and examined him. They slipped an oxygen mask over his face, tore open his shirt so they could attach him to a heartrate monitor, wrapped a blood pressure cuff around his arm, put a splint on a suspected broken wrist and inserted a cannula, ready for fluid replacement and pain relief, and fastened a c-collar around his neck.

"He allergic to anything? Morphine?" one of the paramedics asked as she pulled a vial from the emergency kit.

Severide just shook his head. "No, nothing." The paramedic then quickly pushed the morphine into the cannula in Casey's hand.

"The chopper's about a minute out," the other paramedic told Severide as they began to prepare Casey for transport, rolling him as gently as they could onto a backboard and wrapping him in a fresh blanket. Casey was hardly aware of anything that was happening around him now, his world was just a blur. The paramedic turned her attention to Severide, "Right, let's have a look at your…"

"I'm all right, we've just got to take care of him," Severide responded, "I can travel with him, yeah?"

"Yeah," she nodded, "There should be space."

The engine clatter of the helicopter was soon overhead as it hovered, searching for the best landing place. Severide shielded Casey as the rotors whipped up a storm of wind and rain around them as the pilot brought the craft down nearby. The doors opened and the on-board doctor and paramedic raced over with a gurney, ready to get Casey boarded and transported to the nearest trauma centre.

Casey was lifted up on the backboard and onto the gurney, with another exchange of information between the paramedics and the air evacuation crew. Severide stayed closely by him. "Kel…" he whispered under the oxygen mask, barely audible with the roar of the engine and rotors.

Severide grabbed his hand and they strapped him onto the gurney and rolled him over to the waiting chopper. "We're goin' for a little ride Matty, you ever been in a chopper?" he asked, trying to keep himself calm for Casey's sake although that was the last thing he felt.

"No… no… don't like flying…" Casey slurred his words a little now but he could make himself understood.

"You don't like flying? Why didn't I know that?" Severide questioned, although he supposed it made sense, as long as he'd known Casey, which was more than ten years now, he'd never known him to fly anywhere and now that he thought about it he couldn't imagine him getting on a plane to go away on holiday in his youth. Plus he knew how much Casey liked control so it made sense. He didn't have chance to say any more to Casey as he was loaded into the helicopter. He climbed in after him and the doors were closed. "You'll be just fine, I promise, won't even realise you're flying," he clutched Casey's hand comfortingly, more from instinct than conscious thought. He watched as the doctor pumped another syringe into the cannula in Casey's other hand and smiled gratefully, realising it must be more pain relief.

As the chopper began to lift off Casey's eyes flickered closed. Severide could see how swollen the left side of his face and his left eye were now, various shades of bruising had spread across his pale skin. He was sure both of them would be black and blue soon. The marks left on the road by the collision told the story. The distance they'd travelled whilst they'd both been unconscious told Severide the car must have flipped right over, he couldn't remember anything except the fear in Casey's eyes when he realised he wasn't going to be able to avoid the crash.

Whilst keeping an eye on Casey's vitals the doctor and on-board paramedic checked Severide over for injuries. All the time Severide kept his focus on Casey, wincing as he was examined, poked and prodded. "What hospital are we going to? How long will it take?" Severide asked.

"Closest trauma centre, Saint Barts," the doctor replied, "Twenty minutes."

Still looking at the monitor by Casey's side Severide spoke, "He's gonna be all right? Isn't he?"

"Quicker we get to the hospital the better," the man replied. A non-answer.

"Did I make things worse?"

"No," the doctor replied honestly, "The pressure of the collapsed lung on his heart would have caused him to go into cardiac arrest, you wouldn't have been able to get him back from that. You saved his life."

"I can't lose him," Severide was shaking his head, "I can't."

Just then the monitor blared out. Casey's pressure was dropping. The doctor leant over him, pulled away the blanket, the cold end of the stethoscope touched Casey's skin. "His lung's collapsed again…" He pulled out a kit from the side of the helicopter. "Needle decompression…"

Severide watched helplessly as the doctor and paramedic worked on keeping Casey alive long enough to get him to the hospital. He'd have given anything to be in Casey's position right now, for him to be lying there and Casey just to have a few cuts and bruises because the man didn't deserve this.

"He's awake," the doctor announced. He moved away slightly, there wasn't much room in the craft, so Severide could get to Casey's side.

"Kel…" Casey's voice strained.

"Hey bud, you're doing really well." Severide smiled down at him.

"I… I don't…"

"Shh…" Severide soothed, "Save your energy…"

"What… what happens… will I see her… again? What happens?" he coughed out, red specks covering pale skin. "Please… Kel?" he asked, searching Severide's eyes.

"Yeah." Severide just nodded, staring into Casey's eyes, he knew he'd never be able to shake the image of Casey's distress from his mind for as long as he lived.

Casey calmed down immediately, he visibly relaxed as he spoke, "That's… that's not… not so scary… then…"

"You don't need to be scared," Severide replied, "I promise you're going to be just fine. I promise, Casey."

"Shouldn't… shouldn't make promises… can't keep… I'm… I'm falling…"

Severide grabbed his cold hand, shaking his head. "You're not falling. You're right here, you're right here… Matt? C'mon… not now, just stay awake, you gotta keep those pretty eyes of yours open… Matt… Matty…"

 **TBC**


	3. Hotel

**Promises**

 **Hotel**

Casey and Severide had been at the small hospital for several hours now. Severide hadn't seen Casey since he was taken off the helicopter. He had been reassured Casey was doing well but he'd been told nothing more as he'd had his own injuries attended to. He was suffering a minor concussion, a lot of bruising, although far less than Casey. His dislocated shoulder had thankfully easily been reduced by external rotation, meaning his arm only needed the minimal support of a sling and he could still use his right hand. Casey's injuries had taken a lot more attention. The doctor had been forced to intubate him before the helicopter landed on the roof of the hospital, as he pumped oxygen into his precious body the paramedic squeezed the IV bag of saline, all in an attempt to increase Casey's pressure. Fortunately all their measures had worked and Casey arrived at the hospital with a low but steady blood pressure and a good oxygen saturation rate. Severide had been separated from him almost immediately at the point of landing. There wasn't enough room in the elevator for both of them and the trauma team. Severide hadn't seen him since.

Severide would have been pacing up and down as he waited for news on Casey if they hadn't given him a shot of strong painkillers. He wasn't being admitted thankfully but there wasn't anywhere else he wanted to be. He could hardly begin to imagine the gut wrenching fear that Casey must have suffered whilst he had been waiting for news on Hallie. It must have been ten times than what he was feeling now waiting for Casey. They may have reassured him Casey was doing well but he was still desperately anxious to see the proof, to see Casey alive and recovering. He'd come so close to losing him, he didn't have many people in his life, not close friends like Casey, he'd always felt closer to Shay, Andy and Casey than he had to his family. They were family but Andy was gone now. He couldn't ever lose Casey.

"Kelly Severide?" a female voice asked him suddenly. He peered up wearily, he hadn't noticed as a woman in scrubs had approached.

"Yeah," he replied, standing up, having to steady himself on the chair. "How is he?" he asked.

"Very well considering. He shouldn't need surgery," she informed him.

"Shouldn't?"

"We're positive the bleeding will stop on its own so we don't want to open him up unnecessarily," she responded. "We tried to contact his next of kin but…" she began.

Severide's heart sank and he sat back down before his legs gave out. Of course Hallie would still be shown as his emergency contact, changing it would have been the last thing on Casey's mind. "She died four weeks ago," he explained, "He doesn't have any other family." That wasn't strictly true, but with his mom in prison and his sister as good as estranged Severide was the closest thing he had to family, along with the rest of 51. "I can sign anything if you need? I'm his best friend, I work with him, we're firefighters," he spoke.

She smiled. "I did hear how you saved his life in the field."

He shrugged off her compliment. "Anyone else would have done the same."

"No, they wouldn't have had the skills to do what you did," she responded. This time he smiled, thinking back to how it was Casey lying there, telling him what to do. Casey had managed to save his own life. Severide wasn't at all convinced he'd have been able to do it correctly if it weren't for his instructions.

"Doctor…" a nurse started as she walked up to them, "He's awake."

The doctor turned to her and thanked her.

"Can I see him?" Severide asked, already getting up again.

"Come with me," she replied. As they walked to the trauma bay she spoke, "He's still intubated but he should be fairly lucid…"

"He's not going to be in any pain, right?"

"No he shouldn't be in any pain at all," she responded, "He's been cleaned and stitched up, the scans revealed broken ribs and a severe lung contusion, but you already knew that. His left wrist was broken, the cast is just setting. It wasn't a bad break. He's gonna be very sore and bruised for a while, you both are. He's got a couple of chest tubes in but they'll be taken out in the day or so, and he should come off the ventilator within the next twenty-four hours, we're just giving his lungs a bit of a reprieve. Do you have any questions? I know that's a lot of information."

They were standing outside the trauma bay now. Severide looked over Casey before he stepped inside. He didn't look anywhere near as pale as before but he was still nowhere near his usual colour. He did look better now the blood had been cleaned from his face but he was littered with a multitude of bruises from dark purple to pale yellow and green. Some of the cuts on his face had been stitched and dried blood still matted his hair in places. He was lying almost flat with his head propped on a small pillow, wearing a pale hospital gown and covered in a sheet and blanket. Severide could see various tubes snaking out from under the bed covers. He glanced at the monitor and smiled a little, Casey really was much more stable now and having heard that he shouldn't need surgery was a blessing.

When he stepped inside the smell of antiseptic filled the air, he went straight up to Casey's side. "Hi Matt," he spoke softly, if Casey felt anything like he did he was sure he'd have a roaring headache right now despite the pain relief. The doctor remained back, satisfied that Severide knew what he was doing and satisfied that Casey was still doing well. "You're in the hospital," he continued, unsure quite what Casey would have been told, or would remember.

Casey weakly moved his right hand slowly up to the tube in his mouth but Severide took it gently and laid in back by his side, not letting it go.

"That needs to stay in for a bit but you don't need to worry, you're all right," Severide smiled, "And I'm fine too. Want to blink once for yes and twice for no?"

One blink.

"Good," Severide nodded, "Do you remember what happened?"

After a moment Casey blinked again.

"Good. Are you in any pain?" he asked, still gently holding Casey's hand.

Severide smiled as Casey blinked twice.

"Ok, that's really good, you just need to rest now, ok?" he said but Casey was shaking his head, "It's all right, everything's ok, you won't be here long, I'm fine, they're not admitting me, I'll speak to the cops, I'll sort out the truck, you really just need to rest. I'll be right here when you wake."

He could see the tension leave Casey's face as he finally allowed himself to close his eyes and relax.

"He worries too much about everyone and everything and never about himself," Severide voiced his own thoughts aloud.

"Seems like he has you to worry enough for him," the doctor responded, Severide had almost forgotten she was in the room. "He'll make a full recovery," she reassured him again, "We'll be getting him transferred up to a private room soon. Is there anyone we can call for you?"

Severide shook his head, "No, I'll sort myself out, thanks."

Casey was soon moved up to a private room. Severide remained with him, the staff made no objections when he stayed with him overnight which was good because he still hadn't called Shay, who he was sure would come to their aid once he informed her what had happened. The police had been and taken Severide's statement. The wrecked truck had been brought to the city pound and their belongings boxed and stored at the police headquarters. Eventually the police would also interview Casey once he was free of the tube and able to speak again. Severide had also spoken to Casey's vehicle insurance company, explained their position and sorting out what needed to happen next so Casey wouldn't have to worry about any of it. He'd showered in the private bathroom and changed into some scrubs the hospital had provided for him but Severide didn't sleep until late the day after the accident. He'd finally shut his eyes and relaxed a little once the doctor extubated Casey and his oxygen levels remained stable.

Severide was sitting in the room eating some food he'd bought from the cafeteria when Casey woke lucidly for the first time since the endotracheal tube had been removed, but his first words shattered Severide's heart.

Casey had woken up to a familiar sterile kind of smell and familiar sounds. He finally managed to force his eyes open and what he saw confirmed his thoughts. He was in the hospital but something was different, he couldn't quite pin down what it was. "Hals…" he whispered, his voice was raspy and his throat raw from the tube. "Hals?" he repeated, louder and clearer this time as he looked around the room. His head hurt like hell and his face was sore and bruised, his left eye almost swollen shut now.

Severide stood up and went up to Casey's side. "Hey Matt, it's me, it's Kelly."

"Hallie?"

Severide hesitated. "It's just me. How are you feeling?" he asked.

"What happened?"

"You don't remember? You're in the…"

"Hospital," Casey finished for him. A moment later he eyes fully opened. "Oh crap… the truck… wait… you all right? Did I hurt you?"

"I'm fine, Matt. How are you feeling?"

"Sore all over," he admitted.

"Yeah, I'm not surprised," Severide responded. He pulled the chair over to the bed and sat back down.

"What hospital?"

"Saint Barts, Madison," Severide told him.

He frowned as he thought for a moment, trying to think but whatever medication was going through the IV line was making it hard to focus. "How long?" he asked.

"Accident was yesterday, it's almost 6pm," Severide informed him.

"You're stuck here? You should go home."

"You want me to go?"

"Don't know why you're here," Casey responded tiredly, his walls quickly erecting around himself.

"The same reason we were going on this trip to start with, I care about you."

"Well, suppose you've seen that I'm awake now, you know I'm fine so you don't have to be here."

"Right, yeah, well, I'll call Shay and…"

"Yeah, sounds good," Casey spoke over him, cutting him off mid-sentence, closing his eyes and turning his head away.

"Matt…" he began but he didn't know what else to say. All he knew was that he didn't want to leave Casey alone right now. "It wasn't your fault," he announced, "The car crash… Hallie's death… Andy's…"

Casey's eyes opened.

"None of it was your fault," Severide reiterated.

"Not convinced," he replied wearily after a few moments.

"I know," Severide nodded, "So, I'm just gonna keep reminding you."

Casey was silent in thought for a moment. "Everything was perfect, just then… but I woke up and she was still dead… fucked up, isn't it? Sometimes I still think we need to wait for Andy but… and now I'm expecting her to call me. I kept thinking she was lying next to me in bed," he laughed self-deprecatingly, wincing as he jarred his ribs. "I'll be sleeping on the couch for a very long time. And now I've almost killed you. Thought I had killed you."

"If I'd have died it wouldn't have been your fault," Severide pointed out.

"We wouldn't have been there if I wasn't so weak, if you didn't think I needed a break from everything…"

"Matt, stop," Severide spoke gently. "Like I said before, you're allowed to breakdown. And you're allowed not to get back up straight away. Now, get some more rest because you really do need it. Are you in any pain?"

Casey shook his head a little but his face told Severide otherwise.

"Matt?" he questioned suspiciously.

"Maybe a little," Casey admitted. "You really do need to go home though," he added.

"No I really don't. Close your eyes, I'll get someone to give you a shot," Severide said as he stood up stiffly.

"Kel…" he murmured as he let his eyes close.

"Yeah bud?"

"Thanks."

Later that evening Severide made a lengthy call to Shay and told her everything that had happened. Once she was reassured that there were both going to be fine they came up with some plans of action. There were a few options and ideas they discussed. Casey could be transferred down to a hospital in Chicago but it was unlikely that he'd need to stay in hospital once the chest tubes were out. So it would be simpler for Casey to stay where he was until he was ready for discharge. Severide would book a room in a hotel for the next couple of nights and Shay would drive his car up to Madison when Casey was discharged, then Severide could drive them all back to Chicago, provided his shoulder was up to it. It meant that Casey wasn't going to be left alone in a strange city even if he insisted he would be fine, Severide and Shay knew better.

Casey was up and about a couple of days later. The chest tubes had been removed. He was no longer coughing up blood and his vitals were stable without any supplemental oxygen or fluids. He was in a lot of pain but didn't ask for any extra painkillers and when anyone asked he would say he felt fine, just a little sore and bruised despite the agony his body felt. He was spending a lot of his time asleep which Severide was grateful for, although it did worry him too. Severide knew Casey needed his rest but at points it felt like he was avoiding reality, avoiding a world without Hallie. When Casey was awake he'd stare blankly at the tiled ceiling or pale yellow painted walls, and most of the time he didn't even try to feign interest in anything Severide was saying and still insisted he should have gone home.

"Morning Case," Severide said cheerily as he came into Casey's room. It was his fourth and final day in hospital and he was due for discharge before mid-day. He picked up a piece of the toast on Casey's side table and sat himself down in the chair by the bed.

"You know the hospital has a cafeteria and it's open, right? You can get your own breakfast," Casey commented.

"Because you're gonna finish yours?" Severide retorted sarcastically, chewing on the toast.

"Fair point," Casey shrugged.

"You'll be unrecognisable when you get back to work," he went on, "A diet of booze and little else isn't gonna help you feel any better."

"Oh, so we're having _that_ conversation?"

"Just keeping my eye on you just like…"

"Just like Hallie would have wished?" Casey questioned incredulously, "You don't know what…"

"Yes I do," Severide interrupted firmly. "I do know," he paused, as if gathering courage, sorting his thoughts. "Matt, I really do need you to promise me one thing. It scares the hell out me, it's been keeping me up at night."

"The great Kelly Severide scared?"

"I need you to make one promise, just one, I'll never ask you for anything else again," Severide spoke, "Promise me that you won't do anything… anything stupid."

Their eyes locked for and there was a slightly uncomfortable silence for a few moments before Casey answered. "Don't worry, I'd never do anything like that."

"Good 'cause I didn't stick a knife in your side for nothing," he let out a breath of relief before going on, "I know things are bad right now but I also know we'll get through this."

"I'm not going to self-destruct, I promise Kelly," Casey responded softly. The fact that Severide had said 'we'll get through it' and not 'you'll get through it' wasn't lost on him.

Severide nodded, "Ok and sorry, you… you just make me worry sometimes… all the time." Severide admitting his feelings was something almost as rare as Casey doing the same, and as he spoke, he caught a flash of something in Casey's eyes. A look that he hadn't ever seen before but it was fleeting and as they dropped eye contact the moment was over.

"I know," he smiled. "It's kinda nice," he shrugged after a moment, "I'd hate something to happen to you too."

"Well we better try and stay out of trouble then," Severide grinned back at him, his face lit up, eyes sparkling.

"Yeah 'cause that's likely," he laughed, gripping his side, "Ow… ok… no laughing."

Casey was sleeping peacefully when Shay arrived at the hospital in Madison later that morning. Severide left Casey's room to meet with her in the corridor. "Hey, look at you Kelly…" she greeted with a gentle hug, looking at the grazes and bruising on his face, "How are you feeling? You look terrible."

"Thanks," Severide responded wryly.

"How's Matt doing?"

"Well, if you think I look awful…" Severide rolled his eyes. "Cops spoke to him yesterday. The guy who hit us was as high as a kite. Matt couldn't have done anything to avoid the crash. His truck's totalled but…"

"But you both made it out," she said, still thankful of that.

Severide turned his head and gazed into the hospital room, his eyes focused on Casey's bruised and battered sleeping form. "I didn't think he was going to make it," he exhaled deeply, "Don't want to relive anything like that again."

Shay placed a comforting hand on his shoulder. "He's going to be all right, Kelly," she spoke, "He'll heal. Physically and mentally."

"He's just so… so sad…"

"Give him time. He's still grieving for Hallie, will for a while yet but he'll heal," she repeated, "You know why I know that? Because he has you, and me and everyone at 51... but most importantly; you."

Severide just nodded, barely taking in what Shay was saying, all his attention was still on Casey. "I'm not sure we should drive back today," he began. "He's gonna be discharged in about an hour, we could quickly go and pick up our stuff from the police station, get back here then get another hotel room, mine's got two doubles though so guess we could share…"

"I'll drive back if you don't feel up to it?"

"No, it's not me, I'm…"

"Worried about Matt," she smiled cheekily.

"It's a long journey, it's not gonna be very comfortable… but yeah, actually, let's say I don't want to, say my shoulder's acting up."

"Good thinking Lieutenant Severide," Shay grinned, amused at Casey's stubbornness. Both of them knew very well he would insist on them going back to Chicago straight away even if he still felt too ill and sore.

It was after mid-day when the doctor had been round and finally signed Casey's discharge forms, satisfied that he was well enough to leave their care. Severide was pushing Casey along to the main exit in one of the hospital wheelchairs, an orderly was walking alongside them and Shay was carrying a bag containing the medications Casey had been prescribed. Casey had protested that he didn't need 'a damn wheelchair' but hospital policy made it compulsory for him to be in it as far as the exit, and the look Severide gave him made him back down immediately. He looked even paler now he was out of the hospital gown and wearing a dark sweater and joggers but it did make the bruises look like less of a contrast.

"Do you need anything for tonight? We can call by a store if you want?" Shay was asking Casey as the main doors opened automatically in front of them and Severide wheeled Casey outside, he shook his head in response. He stood up, still stiff and in pain, but he thanked the orderly, saying he hoped he wouldn't see him again soon. They smiled their thanks and goodbyes and started to make their way to Severide's car. Shay had parked as close to the exit as possible after picking up their things.

As they walked over to Severide's car Casey started to lag behind, he began to feel lightheaded. They were just about turning the corner to where the car was parked when Casey stopped, having to bend over a little and rest his hands on his thighs. Shay and Severide realised Casey was no longer with them, they stopped and hurried over to him.

"Matt," Shay began, seeing his distress, "What's wrong?"

"Dizzy," he breathed, closing his eyes, "Gonna be..." He didn't manage to get any more words out before he began to throw up, retching and heaving. His ribs and chest burned as he threw up the meagre contents of his stomach, until nothing was left but bile.

Severide had been holding him the entire time even though he was barely aware of it as his head spun and his insides rebelled. "You're all right Matt, you're ok," Severide reassured him, unconsciously circling a hand on Casey's back, watched by Shay's observant eyes, making her smile.

"Sorry…" he muttered once the heaving had subsided.

"Don't," Severide said simply, smiling at Casey's habitual need to constantly apologise for everything.

"Your shoes..." he croaked, wiping his mouth with his sleeve.

"Ah yeah," Severide looked down at his shoes, splattered in undigested food, "Don't worry about it. How are you feeling now?" His hand was still on Casey's back.

"Tired. Crappy," Casey responded, taking hold of the bottle of water Shay had passed to him from one of their bags. "Thanks," he said gratefully, flipping back the cap and taking a mouthful.

"And this is why it's a good idea to stay here for at least another night, ok? No arguments. The room's already booked anyway," Severide tried to sound casual, he smiled to hide his worry. He hated seeing Casey so unwell.

Casey didn't protest, he just nodded.

They soon arrived at the hotel and got the stuff they would need for the night out of the car. Severide was pleased they had somewhere to recuperate for another twenty-four hours or so before they had to start the long drive back to Chicago. By the time they got to their room Casey was almost at the point of collapsing where he stood, so Severide dumped the bags down and helped Casey take off his jacket and hoody, careful not to cause him any pain. He pulled back the covers with his free arm and helped Casey down onto the bed, his eyes were closed before his head had even hit the pillow. Severide pulled off his boots and then covered him up with the sheets and blanket.

Shay put her bag onto the floor and sat herself on the other bed whilst Severide laid himself on top of the covers next to Casey's sleeping form, watching him intently. "Get a room you two," Shay said softly, almost jokingly, smiling at Severide. "Oh wait…" she grinned.

Severide smiled back at her and held an index finger up to his lips. "Shh… don't wake him."

She stood up. "I'm gonna get a coffee from the machine, want one?"

Severide nodded and she slipped quietly out of the room. He then laid his head on the pillow, relaxing onto the bed. The movement disturbed Casey. "You in my bed?" he murmured.

"Do you mind?" Severide asked.

"No."

 **The End**


End file.
